Insulator-pin.



C. L. PEIRCE, In.

INSULATOR PI'N.

APPLICATION FILED 050.18. 1912.

Patented Aug. 29,1916.

ED STATES PATENT OFFICE. if

' CHABLES'L. PEIRCE, JR... or PITTSBURGH, PENNSYLVANIA, ASSIGNOROF-ONEHALF 'ro' HUBBARD sYLvAivm.

& CO., OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN- msnm'ronrrm.

Specification of Letters Patent. P t t 29 19 Application filed December18, 1912. Serial No. 737,367.

- To'allwhom it mgayeconcem: I Be it known that I, C ARLES L. PIERCE, Jn, --a citizen of the United States, residing in Pittsburgh, county'ofAllegheny, andState of Pennsylvania, have invented certain new anduseful Improvementsin Insulator- Pins, of which the following is aspecification.

My invention relates to improvements in insulator pins, 7 and ivmoreparticularly to 10 pins for "carrying high-tension wires, and

which are necessarily of considerable height and subjected to severestresses.

-While the principal object of my invention is to construct an'insula'tor pin that will not break or bend under severe strains,and-which'will provide a rigid and durable structure, I furthermore seekto provide a pin fromv which an insulator may be read-- I ily'. removed,and one"embodying a structure 1116 parts of which are of minimum weight,

are readily set up, which may be packed ,for shipin'ent in a smallspace;

Still, a further-object of the invention is to provide a pin'witha-remoya'ble base, so

.25 that the same pin maybe used witlrbases of various required'shapes.Further advantages of the invention will be more specificallyreferred tointhed'e- 'scription and set forth in thedrawings, in which- V Figure 1is an elevational view of my improved sectional pin with a part broken'away and other parts in section; Fig. 2 is a detail sectional-view oftheltop portion of .a modifiedform of pin. Fig, 3 is an elevationalview'of what I term my single sectional pin with parts broken away andother parts in section. -Fig. 4 is a detailsectional view of the to'pportion of a fur- 40 flier-modified form of pin. l

Referring-now more particularly to the .drawing, a suitable bolt 4having a threaded lower end 5 to which a nut 6 is applied, and a headorathreaded or corrugated up- 15 per end 7 constitutes the main meansfor securing'the pin to its support and the insulator to the pin. Theinsulator pin consists, in part, of a metallic shell or truss 8 which isshown in Fig. 3 as consisting of a single piece of sheet metal, whichmay be either 'drawn'or rolled into cone form or any other suitableshape so as to form a truss, and the upper smaller end of which isprovided with threads or corrugations 9.

In the preferred form, the bolt is separably attached to the'shell tofacilitate packing in a small. space for shipment, and to allow the.using of bolts of various lengths with the same shell-whenreqnired bysupports of various thicknesses, but it may be welded or otherwisepermanently attached thereto.

Obviously an insulator might be cemented or otherwise secured directlyto the shell 8 at its corrugated end, and ample strength would beprovided in the construction herein described so far,- but it isadvisable to quake provision for quickly removing and replacing thensulator in case of electrical orother injury thereto, and to providefor such removal and replacement separable thimbles adap'tedtohecemented into the insulator and to be screwed to the pin areadvisable. Present types of pins having this sep;.rable thimble. featureare. weak atfthe trnss or shell, as either thetr'uss only or thesecuring bolt onl v extends into thethimble.

7 joint between the thimble and the-main Frequent breakages occur -atthis.poi'r'it.- In

my structure, it. will be noticed that both the securing bolt and theshell extend into thethimble and the joint is thereby. reinforced.Because of the limited dimensions imposed .by general insulator design,this -feature is obtainable only by the use of a thimble with thinwalls. I provide a thin walled thimble, and at the same time a thimbleof the requisite strength-andductility by drawing the same. up from flatsheet metal and rolling corrugations therein which provide internalsecuring threads and corresponding exterior cement-retaining grooves.-

As insulatorpins are largely used. on

wood supports, it is desirable that a broadhase be provided upon whichthe shell 5 may rest. Itis also desirable to reinforce the lower edge ofthe shell 8 against spreading under severe strains, and also to retainthe bolt 4 in the center of the shell to secure the'full benefit of thetrussconstruct-ion. As the wood supports upon which insulator pins areused aremade both with fiat and convex upper surfaces and of variouswidths according to the character of the construction, it is essentialthat insulator pins befurnished with various forms and sizes of bases.To obviate the necessity of 'gral connectin carrying stocks of completepins of each de sired form, I provide a removable base so that bycarrying extra bases only the pins may be assembled to fit the desiredsupport. A further important object of the removable base is tofacilitate the packing of all the parts of these pins in a minimum ofspace. A large number of bolts may be packed in one case without wastespace. A large number of shells may be nested one within the other intoa small space and the bases will likewise pack closelytogether; allowingthe packing of a dozen pins of my design within the space required forthree or four pins of usual present types. This feature is of immenseimportance because of these insulator pins being largely used inunsettled country where transportation is a. difiicult problem. To thisend, therefore, I make the base 13 separate from the shell 8, and provide the same with a retaining annular groove 30, formed by thecorrugations 14 and 29, in which groove the lower end of the shell 8rests. The inner corrugation 14 is higher than the outer corrugation 29to prevent water seeping into the interior of the shell and running downthe bolt hole 17 in the support'lfi thereby tending to decay andotherwise injure, the support: In Fig. 1 the base 13 is'shown adaptedfor a support with flat top; In Fig. 3 the base 13 shown is for asupport with a convex lt is obvious that when desirable, intemeansbetween the lower end ofithe shel 8 and the base 13 may be provided. I

The securing of the'shell to its support will. be readily understood bymerely stat ng that when the parts are assembled, by turn ing upon thenut 6, the upper end of the bolt will. be drawn toward the support, thusfirmly and rigidly locking the shell upon the base 13.

The sizes of insulators vary according to the voltage for which thy aredesigned. In-

sulator pins are therefore also made in various sizes. In Fig. 1, I showa sectional structure whereby pins of various lengths may hc assembledby using 1, 2 or 3 shell units. It is obvious thatwith this structure, asmaller investment in stock will serve to meet the possible demands forpins of different lengths thanwould be required if a stock of completepins of each size had to be carried. I Yet in this structure none of theessential. features of strength, lightness, and facility of packing arelost. In this structure, Fig. 1, the top section 19 is provided with athreaded or corrugated interior for attachment to the bolt 4, whilethemiddle section 20 and the lower section 21 are each slightly reducedin diameter at their closed upper ends, forming annular shoulders 22 and23 upon which the lower edges of the construction, which I deem withinthe scope of my invention, wherein the bolt 4 is provided with anenlarged threaded or corrugated end 24, the lower edge of which forms ashoulder 25 that engages the upper edge of the shell 8. \Vhere a bolt ofthis construction'is employed the upper end of the shell 8 is open andthe parts are so proportioned that the shoulder 25 rests upon the upperedge of the smaller end of shell 8 and thus when the bolt is drawnby-the nut 6 the shell will be forced against the base plate 13. In Ithis modified form the thimble .26 is pro vided with suflicient threadsor corrugations 27 so as to engage the threads or corrugations on theend 24 and the skirt 28 is made somewhat longer than the skirt 12 inorder to provide a greater bearing surface to re sist the strain. 7 V

In Fig. 4 the bolt 4 is the same-as shown in Fig. 2 with thecorrugations onth'e end of the bolt omitted. Corrugations or threads 31are formedon the shell 8 and complementary corrugations or threads 32are formed on the lower end'of the skirt 28 and the two parts may besecured, together. by either screwing or cementing- It is obvious thatthere are many other ways of securing the shell to the bolt, and,therefore, without confining myself to the particular details ofconstruction herein shown,-

I claim:

1. An insulator supporting pin structure comprising a metal truss. abolt extending throu h the truss and threaded at its upper end, t eupper end 'of the truss cooperating with the threaded end of the bolt tolock the bolt against downward movement in the truss, and an insulatorsupporting thimble surrounding the threaded section of'the bolt and theupper end of the truss.

2. An nsulator supporting pin structure comprising a hollow trussadapted to rest on a support, a bolt extending through the trussreceiving the upper end of the bolt and the truss, said bolt havinginterlockingengagement with said truss to be held against downwardmovement therein independently of said thimble, said thimble when aplied intimately surrounding said interloc ing connection.

l. uptwflln pin strmiww- 121 tmt a bolt, and A, ug fin; upper and of w i50% having interlocking upper cud of the truss inst dcmm'nrd wow 1,! thethimble, said

